The air castle in the picture is actually a tea house, bulit in Chino, Nagano Prefecture, Japan.
The tea house is built atop two chestnut trees, cut from a nearby mountain and transported to the site, and is accessible only by free-standing ladders propped against one of the trees. The building’s own is Fujimori, who designed and built the whole house.
The interior is covered with plaster and bamboo mats. Shoes are taken off at the midway point. Once inside the room, which is padded simply with plaster and bamboo mats, the architect’s adventurous spirit gives way to the serenity more suited to the purpose of making tea and calming one’s mind.